1. Field of the Invention
The present invention relates to a servo detection control system, especially to a servo position/stress detection control system that provides position and/or stress control of high precision.
2. Description of the Related Art
Driving mechanism of a conventional precision machine may be combined with displacement or force detecting devices for making the precision machine meet the requirement of expected precision.
Foregoing displacement detecting device may be a linear optical scale wherein the optical scale applies moire method by making lights pass through condensing lens, a first graduated scale, a second graduated scale and a light detector to bring moire fringe effect on the light detector. Light signal may be amplified and be converted into a displacement signal and send back to a control device of the precision machine for measurement.
The displacement detecting device using linear optical scale can present variances of lengths or angles in digital type and quickly reads the variances to avoid interpretation error of human operation. However, design of the optical scale can hardly achieve a zero degree angle between gratings of the first and second graduated scales optical scale. Therefore during light transmission and signal amplification, precision degree achieved by the machine operation still do not meet requirements.
With regard to the force detecting device, it detects output force of a precision machine exerting on a load for correcting the output force of the precision machine before using the precision machine and proceeding actual workpiece machining. However the force detecting device may be easily affected by mechanical equipment and cannot actually and precisely measure the force exerting on workpiece. Therefore precision of machine operation still do not meet requirements.
Furthermore, an electronic press machine is a precision machine using a linear shifting device that drives a molding fixture to press-fit workpieces. The displacement of movement and stress control must be precisely controlled so as to achieve requirements of product quality. Present technique for designing Conventional precision machine produced by present technique can produce products having certain machining precision. Only when the linear shifting device exerting different pressure on workpiece using a press member, press member or workpiece being pressed may have variance of height due to reacting forces and cause the output force and device position cannot be actually reflected and cannot achieve great precision of position.
To overcome the shortcomings, the present invention provides a servo position/stress detection control system to mitigate or obviate the aforementioned problems.